In a room or a space, warmer air tends to move toward the ceiling while cooler air tends to move toward the floor. This results in different temperatures at different vertical levels in the room or space. This natural form of heat distribution by convection is undesirable, since, in a low ceilinged room, a person's head may be in air which is too warm while his legs and feet are in air which is too cool. In a room having a high ceiling, all of the heat may be concentrated at upper levels of the room or space, while persons at floor level may be too cool. Various devices are known in the art for remedying this situation, none, however, being entirely satisfactory. For example, in U.S. Pat. Nos. 3,173,353, 3,347,025, and 3,482,503, devices are shown for propelling warmer air from the ceiling toward the floor. In U.S. Pat. No. 3,827,342 a device is shown for propelling cooler air from adjacent the floor up through a tubular column to be discharged at the ceiling. In U.S. Pat. No. 3,973,479, both modes of circulation are shown. Most of the devices shown in these patents require the disposition of a tubular structure within the room or space, this being unsightly and undesirable. Furthermore, the devices shown in the patents are useful only in the winter months when heating is required, and are not useful for summer operation. Propulsion of warmer air near the ceiling toward the floor will in most cases result in unwanted drafts and discomfort to occupiers of the room or space. This invention provides an improved method and apparatus for circulating air within a room or space to tend to equalize temperatures at all levels of the room or space.